Gastric Mucosal Defense Research Articles

Clinicopathological Study of Gastroduodenal Biopsies and Correlate with Endoscopic Findings in Northeast India- One- Year Cross-sectional Study in a Tertiary Care Centre

Background: The gastrointestinal tract (GIT) is a hollow muscular tube extending from the oral cavity to the anus. Acid peptic disease is among the most common disorders affecting this region globally, caused by an imbalance between acid secretion and gastric mucosal defenses. Endoscopy has enhanced the accuracy and early histologic diagnosis of mucosal lesions. This cross-sectional study examines 100 gastroduodenal biopsies over a one-year period. Methods: The study categorized histopathological findings from gastro-duodenal biopsies collected via endoscopy and analyzed their correlation with endoscopic results. Results: Gastroduodenal lesions were more prevalent in males, particularly in the fifth decade of life. Endoscopic findings included 12 normal cases, 31 ulcers, 15 erosions, 4 polyps, and 38 malignancies. Among the 38 malignancies, 10 were premalignant, 23 were diagnosed as gastric carcinoma, and 4 as duodenal carcinoma, demonstrating a strong correlation between endoscopic and histopathological findings. Conclusion: Endoscopic gastroduodenal biopsies are instrumental in diagnosing both benign and malignant lesions across various age groups and sites. The combination of endoscopy and histopathological analysis provides a powerful diagnostic tool for better patient management.

Untargeted serum and gastric metabolomics and network pharmacology analysis reveal the superior efficacy of zingiberis rhizoma recens-/euodiae fructus-processed Coptidis Rhizoma on gastric ulcer rats

Ethnopharmacological relevanceZingiberis rhizoma recens-/wine-/euodiae fructus-processed Coptidis Rhizoma (CR, zCR/wCR/eCR) are the commonly used processed products of CR in clinic. After being processed with different excipients, the efficacy of CR will change accordingly. I.e., wCR could resolve excessive heat of the upper energizer, zCR could eliminate gastric heat and harmonize the stomach, eCR could smooth the liver and harmonize the stomach. However, the underlying mechanisms were still unclear. Aim of the studyTo further verify the differential efficacy of the three processed CR products and compare the mechanisms on gastric ulcer. Material and methodsFirst, a GU model, whose onset is closely related to the heat in stomach and the disharmony between liver and stomach, was established, and the therapeutic effects of zCR/wCR/eCR/CR were evaluated by pathologic observation and measurement of cytokine levels. Second, metabolomics analysis and network pharmacology were conducted to reveal the differential intervening mechanism of zCR/eCR on GU. Third, the predicted mechanisms from metabolomics analysis and network pharmacology were validated using western blotting, flow cytometry and immunofluorescence. ResultszCR/wCR/eCR/CR could alleviate the pathologic damage to varying degrees. In metabolomics research, fewer metabolic pathways were enriched in serum samples, and most of them were also present in the results of gastric tissue samples. The gastroprotective, anti-inflammatory, antioxidant, and anti-apoptotic effects of zCR/wCR/eCR/CR might be due to their interference on histidine, arachidonic acid, and glycerophospholipids metabolism. Quantitative results indicated that zCR/eCR had a better therapeutic effect than wCR/CR in treating GU. A comprehensive analysis of metabolomics and network pharmacology revealed that zCR and eCR exerted anti-GU effects via intervening in five core targets, including AKT, TNF, IL6, IL1B and PPARG. In the validation experiment, zCR/eCR could significantly reverse the abnormal expression of proteins related to apoptosis, inflammation, oxidative stress, gastric function, as well as the PI3K/AKT signaling pathways. ConclusionzCR and eCR could offer gastroprotective benefits by resisting inflammation and apoptosis, inhibiting gastric-acid secretion, as well as strengthening gastric mucosal defense and antioxidant capacity. Integrating network pharmacology and metabolomics analysis could reveal the acting mechanism of drugs and promote the development of medications to counteract GU.

Gastroprotective effect of eupatilin, a polymethoxyflavone from Artemisia argyi H.Lév. & Vaniot, in ethanol-induced gastric mucosal injury via NF-κB signaling pathway

Ethnopharmacological relevanceArtemisia argyi H.Lév. & Vaniot (AA) has been extensively utilized as an important medicine and food homology in China, Japan, Korea, and eastern parts of Russia, owing to its pharmacological effects, which include anti-inflammatory, antibacterial, antitussive, and antiallergic properties. Despite the extract of AA can significantly alleviate gastric mucosal injury, its precise material basis for effectiveness is not yet clear. As one of the polymethoxy flavonoids with high content in AA, the gastroprotective activity and molecular mechanism of eupatilin (EUP) require further investigation. Aim of the studyThis study aims to investigate the gastroprotective effects and possible mechanisms of EUP by using an ethanol-induced gastric mucosal injury model in rats. Materials and methodsEUP was isolated from 95% ethanol extract of AA using a systematic phytochemical method. The gastroprotective activity of EUP was evaluated using a male SD rat model with ethanol-induced gastric mucosa injury. Histopathology evaluation of gastric tissues was performed using hematoxylin and eosin (H&E) staining. The levels of cytokines in the plasma and tissues were tested using the ELISA kits, while western blot analysis was employed to assess the expressions of COX-2, iNOS, and NF-κB pathway proteins. ResultsA sufficient amount of EUP was obtained from AA through chromatographic methods and identified by NMR experiment. In vivo, experimental results proved that EUP could significantly alleviate pathological features, increased SOD, GSH, and IL-10 levels, and decreased the contents of MDA, TNF-α, IL-1β, and IL-6. Further in vitro and in vivo Western blot experimental results showed that EUP significantly down-regulates the expressions of the NF-κB signal pathway to relieve inflammatory responses. ConclusionThis study demonstrated that EUP could exert gastroprotective effects by inhibiting inflammation, enhancing gastric mucosal defense, and ameliorating oxidative stress, which is beneficial for providing scientific data for the development of gastric protection.

Organoid-Based Human Stomach Micro-Physiological System to Recapitulate the Dynamic Mucosal Defense Mechanism.

Several stomach diseases are attributed to the dysregulation of physiological function of gastric mucosal barrier by pathogens. Gastric organoids are a promising tool to develop treatment strategies for gastric infections. However, their functional features of in vivo gastric mucosal barrier and host-microbe interactions are limited due to the lack of physiological stimuli. Herein, a human stomach micro-physiological system (hsMPS) with physiologically relevant gastric mucosal defense system is described based on the combination of organoid and MPS technology. A fluid flow enhanced epithelial-mesenchymal interaction in the hsMPS enables functional maturation of gastric epithelial cells, which allows for the recreation of mesh-like mucus layer containing high level of mucus protective peptides and well-developed epithelial junctional complexes. Furthermore, gastroprotection mechanisms against Helicobacter pylori (H. pylori)are successfully demonstrated in thissystem. Therefore, hsMPS represents a new in vitro tool for research where gastric mucosal defense mechanism is pivotal for developing therapeutic strategies.

Low dose administration of mature silkworm powder induces gastric mucosal defense factors in ethanol-induced gastric injury rat model.

Gastric mucosa is important to protect the gastric damage against external factors. We previously reported the gastro-protective effects of steamed and freeze-dried mature silkworm larval powder (SMSP) in ethanol-treated rats. However, the factors that promote mucosal formation still remain unclarified. In this study, we evaluated the effect of SMSP on the restoration and maintenance of gastric mucosal layer as well as anti-inflammatory response in ethanol-induced stomach injury in rats. A significant decrease of ulcer indexes, histopathological scores and pro-inflammatory cytokine levels was observed in SMSP-treated group. In addition, SMSP protected the mucosal layer from ethanol-induced gastric damage by increasing the expression of nitric oxide synthases and heat shock proteins, along with promoting genes related gastric mucosal protection and biosynthesis including mucin 5AC and trefoil factors. These results demonstrate that SMSP attenuates the pro-inflammatory responses and strengthens the gastric mucosal layer, thus exhibiting gastro-protective effect against ethanol-induced gastric injury in rats.

Diet and carcinogenesis of gastric cancer.

Several recent studies have corroborated a strong association between diet and gastric cancer risk; investigators have also identified dietary factors that protect against gastric cancer. This review summarizes the literature on this topic and guides future research directions. High-salt intake disrupts the gastric mucosal defense barrier, promoting Helicobacter pylori colonization and penetration of other carcinogenic compounds. Processed foods, processed meats, red meat, alcohol, foods with high dietary fat, and dietary cholesterol increase the risk of gastric carcinogenesis. On the other hand, increased consumption of fruits, vegetables, whole grains, nuts, and a low-salt diet may offer a protective effect. Despite decreases in gastric cancer incidence because of increased identification and treatment of H. pylori , gastric cancer remains one of the most common cancers worldwide with a high mortality rate. This disturbing statistic highlights the importance of reducing and eliminating other risk factors for gastric cancer. There is a strong body of evidence that alcohol, processed foods, high salt intake, high fat intake, and foods with animal products (meats, eggs, and dairy) increase the risk of gastric cancer. A diet that is high in whole grains, fruits, vegetables, nuts and is low in salt may reduce the risk of gastric cancer.

H2S Donors and Their Use in Medicinal Chemistry.

Hydrogen sulfide (H2S) is a ubiquitous gaseous signaling molecule that has an important role in many physiological and pathological processes in mammalian tissues, with the same importance as two others endogenous gasotransmitters such as NO (nitric oxide) and CO (carbon monoxide). Endogenous H2S is involved in a broad gamut of processes in mammalian tissues including inflammation, vascular tone, hypertension, gastric mucosal integrity, neuromodulation, and defense mechanisms against viral infections as well as SARS-CoV-2 infection. These results suggest that the modulation of H2S levels has a potential therapeutic value. Consequently, synthetic H2S-releasing agents represent not only important research tools, but also potent therapeutic agents. This review has been designed in order to summarize the currently available H2S donors; furthermore, herein we discuss their preparation, the H2S-releasing mechanisms, and their -biological applications.

Gastrokine 2 Regulates the Antitumor Effect of JAK2/STAT3 Pathway in Gastric Cancer.

GKN2 (gastrokine 2) mainly plays a regulatory role in gastric mucosal defense and cell protection mechanisms, and its role in gastric cancer has not been thoroughly elucidated. Immunohistochemistry was used to detect GKN2 and TFF1 expressions in 90 gastric cancer tissues, 48 neoplastic resection margins, and 22 normal gastric mucosa epithelia. It showed that the downregulation of GKN2 and TFF1 expressions in gastric cancer tissues was significantly different from that in adjacent normal gastric tissues and distal gastric mucosal tissues. Nevertheless, correlation analysis showed that GKN2 expression in gastric cancer tissues was independent of TFF1 expression. After overexpression of GKN2 was constructed in human gastric cancer cell line MKN28 with the Ad-GFP-GKN2 transfected, cell viability was measured by CCK-8 assay, and migration and invasion ability were analyzed by transwell migration assay and transwell invasion assay. It indicated that overexpression of GKN2 significantly reduced the viability of MKN28 and SGC7901 cells. Overexpression of GKN2 could also inhibit the migration and invasion ability in MKN28 and SGC7901 cells. In addition, upregulation of GKN2 can inactivate the JAK2/STAT3 pathway. Our data suggest that GKN2 and TFF1 play the antitumor role in gastric carcinoma, and TFF1 may not interact or cooperate with GKN2. GKN2 overexpression can inhibit the growth and metastasis by downregulating the JAK2/STAT3 pathway in gastric cancer cells.

Research progress on anti-alcoholic gastric injury active components and mechanisms of Chinese herbal medicine

Alcohol is considered to be one of the main causes for gastric injury, and alcoholic gastric injury has been becoming one of the global health problems, which seriously affects the quality of human life. Many studies suggest that the active components extracted from Chinese herbal medicine can effectively reduce the degree of alcohol-induced gastric injury. The active components and its mechanism of anti-alcoholic gastric injury of Chinese herbal medicine reported in recent five years were preliminarily summarized according to the classification of terpenoids, flavonoids, polyphenols, polysaccharides, volatile oils, phenylpropanoids and alkaloids in this paper. The terpenoids could improve oxidative stress and inflammatory response by regulating relevant signaling pathways. The flavonoids are mainly related to antioxidant and anti-inflammatory properties. The polyphenols mainly regulate the level of relevant factors involved in inflammatory pathway, oxidative stress and apoptosis pathway. The polysaccharides could enhance the ability of gastric mucosal defense factor by inhibiting oxidative stress injury and inflammatory response. Phenylpropanoids could enhance the gastric mucosal defense factor. The volatile oils mainly inhibit H~+/K~+-ATPase activity or inflammatory reaction. Alkaloids are closely related to the inhibition of inflammatory response and the improvement of antioxidant system. This paper aims to provide reference for further research and development of Chinese herbal medicine against alcoholic gastric injury.

Gastroprotective Effects of Fermented Lotus Root against Ethanol/HCl-Induced Gastric Mucosal Acute Toxicity in Rats.

Gastric ulcers are a common gastrointestinal disease across the globe. Alcohol consumption is the primary cause of gastric carcinogenesis and progression. We investigated the gastroprotective effects of fermented lotus root (FL) against ethanol (EtOH)/HCl-induced gastric ulcers in a rat model and the conceivable underlying mechanisms involved. Rats received different doses of FL (50, 100, and 200 mg/kg) or ranitidine (positive control, 30 mg/kg) via oral gavage daily for 14 days. One hour after the last oral administration of FL, the EtOH/HCl mixture was orally intubated to induce gastric damage. Oral administration of FL significantly alleviated the gastric lesions. Moreover, FL also elevated the amounts of nitric oxide and the antioxidant enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase in the stomach. To verify the gastric mucosal defense mechanism, inflammation-related genes were measured. Our results revealed that FL effectively inhibited gastric mucosal damage via downregulation of the nuclear factor-kappaB (NF-κB) response in the stomach. The administration of FL significantly lowered the gastric mRNA expression of inflammation-related genes, including NF-κb1, tumor necrosis factor-α, interferon γ, and prostaglandin-endoperoxide synthase 2, compared with the gastric ulcer control group. In addition, the NF-κB signaling pathway-related protein markers inhibitor of κB (IκB)-α, IκB kinase, and NF-κB were significantly reduced in the FL groups. Taken together, these data suggest that FL administration may have potential as an alternative treatment for gastric ulcers due to its antioxidant and anti-inflammatory effects and its ability to promote the recovery of gastric mucosa.

Use of medicinal plants for the treatment of gastric ulcer in some parts of Southwestern Nigeria

Ulcer is erosion in the lining of the stomach or duodenum. It is caused by disruption of the gastric mucosal defense and repair systems. There has been much interest in natural medicines derived from traditional knowledge of pharmacological properties of plants recently. The major aim of this study was to conduct an ethnobotanical survey of plants used in the treatment of Gastric ulcers in some local government areas of Ibadan, South-West, Nigeria. Five local government areas which have prominent traditional medical practitioners and herbal markets were visited. Ninety-two plants belonging to forty-five different families were recorded. The prominent plants’ families recorded include; Apocynaceae, Loranthaceae, and Lamiaceae. Some of the most frequently used medicinal plants mentioned by the respondents are: Sphenocentrum jollyanum Pierre, Euadenia trifoliolata (Sch. &Thon.) Oliv., Khaya ivorensis A. Chev., Lonchocarpus cyanescens Benth, and Kigelia africana (Lam.) Benth. Most of the herbs were prescribed together with other plants and recipes. Modes of administration were mostly concoctions and decoctions. Cultivation and proper documentation of some of the plants which may become endangered over time is therefore encouraged. Most of the identified plants have been used regularly by the traditional medical practitioners and the efficacies have been proven. Key words: Gastric ulcer, ethnobotanical survey, medicinal plants, traditional medicine, South-west Nigeria.

Expression and effect of Calpain9 gene genetic polymorphism on slaughter indicators and intramuscular fat content in chickens.

Calpain 9 (CAPN9) is expressed in the stomach and small intestine. CAPN9 has regulatory roles in hypertension, heart disease, gastric mucosal defense, and kidney disease. The involvement of CAPN9 has not been reported in the development of chickens. CAPN9 mRNA was found in adipose and muscle tissue in this study. Two linkage single nucleotide polymorphisms (SNP; G7518A and C7542G) in intron 4 were screened from 160 birds of the D2 chicken line. The 2 mutation sites were associated with carcass weight, evisceration weight, abdominal fat weight (AFW), abdominal fat percentage (AFP), and breast muscle percentage (all P < 0.05). Intramuscular fat (IMF) content was not significantly different in the 3 genotypes. But, the AA(7518)/GG(7542) genotype had the highest IMF content, highest breast muscle weight, and lower AFW and AFP. Moreover, the mRNA level of CAPN9 in abdominal fat tissue was significantly different (P < 0.05 or P < 0.01) between any 2 genotypes, consistent with AFW and AFP. In summary, the expression of CAPN9 in adipose and breast muscle tissue is reported for the first time. CAPN9 affected production performance of chickens. As a marker, the linkage G7518A and C7542G polymorphisms in intron 4 of CAPN9 could affect the production traits by regulating mRNA expression. The findings concerning the marker enrich the theoretical foundation for molecular breeding of high-quality broilers.

Formulation and evaluation of embelin loaded pectin nanoparticles for the treatment of diabetes

Matricaria recutita L. (Asteraceae), German chamomile, has been widely used in the traditional Tunisian medicine because of having the powerful health benefits. the current study was conducted to determine the protective effect of chamomile (Matricaria recutita L.) decoction extract (CDE) in ethanol-induced ulcer and oxidative stress on gastric mucosa in rat.Adult male wistar rats were used and divided into seven groups: Control, EtOH, EtOH + various doses of CDE (25, 50 and 100 mg/kg, b.w.), EtOH + famotidine (FAM) and EtOH + ascorbic acid (AA). Gastric ulceration was induced by EtOH (4 g/kg, b.w. p.o.).Firsly, we found that acute alcohol administration leads to mark macroscopic and histologic changes in gastric mucosa. EtOH also induced lipoperoxidation (486.99%), thiol (-SH) groups decrease (40.98%) as well as antioxidant enzyme activity depletion such as superoxide dismutase (SOD) (49.05%), catalase (CAT) (46.80%) and glutathione peroxidase (GPx) (38.20%). Our results also demonstrated that alcohol intoxication increased tissue and plasmatic hydrogen peroxide, calcium and free iron levels. More importantly, CDE reversed all macroscopic, histologic and biochemical changes induced by EtOH administration.A potential gastropreotective effect of CDE against EtOH-induced ulcer and oxidative stress might be partially to its antioxidant properties as well as to various gastric mucosal defense mechanisms, including protection of gastric sulfhydryls and its opposite effect on some intracellular mediators such as free iron, hydrogen peroxide and calcium.

Neuroperptides, their interactions and gastric mucosal protection in the rat.

In the last decades several neuropeptides, such as thyreotropin‐releasing hormone (TRH), amylin, neurotensin, ghrelin, melatonin, opioid peptides, substance P (SP), angiotensin II (Ang II) have been shown inhibit the gastric mucosal lesions induced by different ulcerogenic agents given centrally in the dose range of fmol to nmol. The site of action is likely to be the dorsal vagal complex. However, the different neuropeptides can interact with each other at different levels and can affect each other's biological actions. Among others nociceptin ‐ opioid; angiotensin ‐ cannabinoid, opioid; CRF ‐ beta‐endorphin, somatostatin interactions have been demonstrated. Aim of the present study was to elucidate potential interactions between neuropeptides and cannabinoids in gastric mucosal defense.MethodsGastric damage was induced by acidified ethanol in the rat (150–170 g, males); the gastric mucosal lesions were detected 60 min after ethanol administration. The dugs were given intracerebroventricularly (i.c.v.) 10 min before ethanol challenge. Gastric mucosal CGRP, somatostatin levels were determined by RIA.ResultsThe gastroprotective effect of SP, nociceptin or cannabinoids was reversed by endomorphin2‐antiserum or the opioid receptor antagonist naloxone, while the Ang II‐induced protection was decreased by the CB1 receptor antagonists, AM‐251.ConclusionNeuropeptides have prominent role in central regulation of gastric mucosal integrity. In addition, interactions between neuropeptides result in redundancy in centrally‐initiated gastric mucosal defense.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Modulation of central endocannabinoid system results in gastric mucosal protection in the rat

Previous findings showed that inhibitors of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), degrading enzymes of anandamide (2-AEA) and 2-arachidonoylglycerol (2-AG), reduced the nonsteroidal anti-inflammatory drug-induced gastric lesions. The present study aimed to investigate: i./whether central or peripheral mechanism play a major role in the gastroprotective effect of inhibitors of FAAH, MAGL and AEA uptake, ii./which peripheral mechanism(s) may play a role in mucosal protective effect of FAAH, MAGL and uptake inhibitors. Methods: Gastric mucosal damage was induced by acidified ethanol. Gastric motility was measured in anesthetized rats. Catalepsy and the body temperature were also evaluated. Mucosal calcitonin gene-related peptide (CGRP), somatostatin concentrations and superoxide dismutase (SOD) activity were measured. The compounds were injected intraperitoneally (i.p.) or intracerebroventricularly (i.c.v.). Results: 1. URB 597, JZL184 (inhibitors of FAAH and MAGL) and AM 404 (inhibitor of AEA uptake) decreased the mucosal lesions significantly given either i.c.v. or i.p. 2. URB 937, the peripherally restricted FAAH inhibitor failed to exert significant action injected i.p. 3. Ethanol-induced decreased levels of mucosal CGRP and somatostatin were reversed by URB 597, JZL 184 and AM 404, the decreased SOD activity was elevated significantly by URB 597 and JZL 184. 4. Neither compounds given i.c.v. influenced gastric motility, elicited catalepsy, or hypothermia. Conclusion: Elevation of central endocannabinoid levels by blocking their degradation or uptake via stimulation of mucosal defensive mechanisms resulted in gastroprotective action against ethanol-induced mucosal injury. These findings might suggest that central endocannabinoid system may play a role in gastric mucosal defense and maintenance of mucosal integrity.

Prophylactic efficacy of patchoulene epoxide against ethanol-induced gastric ulcer in rats: Influence on oxidative stress, inflammation and apoptosis

Patchoulene epoxide (PAO), a tricyclic sesquiterpene isolated from the long-stored patchouli oil, has been demonstrated the anti-inflammatory activity in vivo based on our previous study. However, the gastric protective effect of PAO still remains unknown. Therefore, in the present study, ethanol-induced gastric ulcer model was carried out to evaluate the anti-ulcerogenic activity of PAO and to elucidate the potential mechanisms that involves. According to our results, macroscopic examination revealed that PAO could significantly reduce ethanol-induced gastric ulcer areas as compared with the vehicle group, which was also supported by the histological evaluation result. As for its potential mechanism, the anti-inflammatory activity of PAO contributed to gastric protection through reversing the imbalance between pro- and anti-inflammatory cytokines and modulating the expressions of NF-κB pathway-related proteins including p-IκBα, IκBα, p-p65 and p65. Besides, PAO was able to enhance the expressions of antioxidant enzymes including glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), and down-regulate malonaldehyde (MDA), an indicator of lipid peroxidation. Furthermore, immunohistochemistry analysis exhibited potent anti-apoptosis effect of PAO, as evidence by down-regulating the protein expression of caspase-3, Fas and Fasl. Additionally, we also demonstrated that PAO could replenish PGE2 and NO mucosal defense. In conclusion, these findings suggested that PAO has gastric protective activity against ethanol and this might be related to its influence on inflammatory response, oxidative stress, apoptosis cascade and gastric mucosal defense.

Recent Advances in the Gastric Mucosal Protection Against Stress-induced Gastric Lesions. Importance of Renin-angiotensin Vasoactive Metabolites, Gaseous Mediators and Appetite Peptides.

Stress is known to cause severe adverse effects in the human gastrointestinal tract including mucosal microbleedings and erosions or even gastric ulceration but the mechanism of these complications has not been fully elucidated. The pathogenesis of stress-induced gastric damage involves the fall in Gastric Blood Flow (GBF), an increase in gastric acid secretion and gastric motility, enhanced adrenergic and cholinergic nerve activity and the rise in gastric mucosal generation of reactive oxygen species. The gastric mucosal defense mechanisms against the deleterious effect of stress include the activation of the hypothalamic-pituitary-adrenal axis which has been linked with glucocorticoids release capable of counteracting of stress-induced gastric lesions. Here we summarize the novel gastroprotective mechanisms against stress damage exhibited by angiotensin-(1-7), the newly discovered metabolite of Renin-Angiotensin System (RAS), the gaseous mediators such as nitric oxide (NO), hydrogen sulfide (H2S) or Carbon Monoxide (CO), and the food intake controlling peptides ghrelin, nesfatin- 1 and apelin possibly acting via brain-gut axis. These bioactive molecules such as RAS vasoactive metabolite angiotensin-(1-7) and appetite peptides have been shown to afford gastroprotective effect against stressinduced gastric lesions mainly mediated by an increase in gastric microcirculation. Gaseous mediators protect the gastric mucosa against stress lesions by mechanism involving the activation of PG/COX and CO/HO-1 biosynthetic pathways, and their anti-inflammatory and anti-oxidizing properties. Thus, these new components add new mechanistic aspects to the common cooperation of NO/NO-synthase, PG/COX systems and vasoactive sensory neuropeptides including CGRP but their gastroprotective efficacy against experimental stress ulcerogenesis requires the confirmation in human clinical trials.

A novel pH-controlled hydrogen sulfide donor protects gastric mucosa from aspirin-induced injury.

Hydrogen sulphide (H2S) serves as a vital gastric mucosal defence under acid condition. Non‐steroidal anti‐inflammatory drugs (NSAIDs) are among widely prescribed medications with effects of antipyresis, analgesia and anti‐inflammation. However, their inappropriate use causes gastric lesions and endogenous H2S deficiency. In this work, we reported the roles of a novel pH‐controlled H2S donor (JK‐1) in NSAID‐related gastric lesions. We found that JK‐1 could release H2S under mild acidic pH and increase solution pH value. Intragastrical administration of aspirin (ASP), one of NSAIDs, to mice elicited significant gastric lesions, evidenced by mucosal festering and bleeding. It also led to infiltration of inflammatory cells and resultant releases of IL‐6 and TNF‐α, as well as oxidative injury including myeloperoxidase (MPO) induction and GSH depletion. In addition, the ASP administration statistically inhibited H2S generation in gastric mucosa, while up‐regulated cyclooxygenase (COX)‐2 and cystathionine gamma lyase (CSE) expression. Importantly, these adverse effects of ASP were prevented by the intragastrical pre‐administration of JK‐1. However, JK‐1 alone did not markedly alter the property of mouse stomachs. Furthermore, in vitro cellular experiments showed the exposure of gastric mucosal epithelial (GES‐1) cells to HClO, imitating MPO‐driven oxidative injury, decreased cell viability, increased apoptotic rate and damaged mitochondrial membrane potential, which were reversed by pre‐treatment with JK‐1. In conclusion, JK‐1 was proved to be an acid‐sensitive H2S donor and could attenuate ASP‐related gastric lesions through reconstruction of endogenous gastric defence. This work indicates the possible treatment of adverse effects of NSAIDs with pH‐controlled H2S donors in the future.

Protective effect of chamomile (Matricaria recutita L.) decoction extract against alcohol-induced injury in rat gastric mucosa

BackgroundMatricaria recutita L. (Asteraceae), German chamomile, has been widely used in the traditional Tunisian medicine because of having the powerful health benefits. the current study was conducted to determine the protective effect of chamomile (Matricaria recutita L.) decoction extract (CDE) in ethanol-induced ulcer and oxidative stress on gastric mucosa in rat. MethodsAdult male wistar rats were used and divided into seven groups: Control, EtOH, EtOH+various doses of CDE (25, 50 and 100mg/kg, b.w.), EtOH+famotidine (FAM) and EtOH+ascorbic acid (AA). Gastric ulceration was induced by EtOH (4g/kg, b.w. p.o.). ResultsFirsly, we found that acute alcohol administration leads to mark macroscopic and histologic changes in gastric mucosa. EtOH also induced lipoperoxidation (486.99%), thiol (-SH) groups decrease (40.98%) as well as antioxidant enzyme activity depletion such as superoxide dismutase (SOD) (49.05%), catalase (CAT) (46.80%) and glutathione peroxidase (GPx) (38.20%). Our results also demonstrated that alcohol intoxication increased tissue and plasmatic hydrogen peroxide, calcium and free iron levels. More importantly, CDE reversed all macroscopic, histologic and biochemical changes induced by EtOH administration. ConclusionA potential gastropreotective effect of CDE against EtOH-induced ulcer and oxidative stress might be partially to its antioxidant properties as well as to various gastric mucosal defense mechanisms, including protection of gastric sulfhydryls and its opposite effect on some intracellular mediators such as free iron, hydrogen peroxide and calcium.

Nitric Oxide and Hydrogen Sulfide Interact When Modulating Gastric Physiological Functions in Rodents.

The objective was to evaluate the effects of nitric oxide (NO) and hydrogen sulfide (H2S) donors and possible interactions between these two systems in modulating gastric function. Mice received saline, sodium nitroprusside (SNP), or sodium hydrosulfite (NaHS), and after 1h, the animals were killed for immunofluorescence analysis of CSE or eNOS expressions, respectively. Other groups received saline, SNP, NaHS, Lawesson's reagent (H2S donor), PAG+SNP, L-NAME, L-NAME+NaHS, or L-NAME+Lawesson's reagent. Then, the gastric secretions (mucous and acid), gastric blood flow, gastric defense against ethanol, and gastric motility (gastric emptying and gastric contractility) were evaluated. SNP and NaHS increased the expression of CSE or eNOS, respectively. SNP or Lawesson's reagent did not alter gastric acid secretion but increased mucus production, and these effects reverted with PAG and L-NAME treatment, respectively. SNP or NaHS increased gastric blood flow and protected the gastric mucosa against ethanol injury, and these effects reverted with PAG and L-NAME treatments, respectively. SNP delayed gastric emptying when compared with saline, and PAG partially reversed this effect. NaHS accelerate gastric emptying, and L-NAME partially reversed this effect. SNP and NaHS alone induced gastric fundus and pylorus relaxation. However, pretreatment with PAG or L-NAME reversed these relaxant effects only in the pylorus but not in the gastric fundus. NO and H2S interact in gastric physiological functions, and this "cross-talk" is important in the control of mucus secretion, gastric blood flow, gastric mucosal defense, and gastric motility, but not in the control of basal gastric acid secretion.